So what headers fit my mach 1? is it all 1 5/8 headers? what makes them fit compared to a GT header, Im looking on brenspeed and they have 1 5/8 headers listed for a GT, is this right?

 

You need to make sure it says for 1999/2001 cobra and 03-04 mach 1 specifically. The exhaust outlets for the 2v and 4v motors are different. I believe they are slightly different on the 03/04 cobra compared to the mach 1 and previous cobras as well, but I'm not sure if it is substantial enough to require a completely different header for 03/04 cobras over mach 1s. maybe someone else can explain that in more detail.

Bottom line is, a set of headers for a GT will NOT fit a 4v.

 

fwiw on the lethalperformance website the kooks headers i plan on getting share the same part number from 03/04 cobra to 03/04 mach 1. the gt headers will not work on a 4v..at least from what i have seen on the forums. but it looks like the cobra and mach headers will work on either car.

http://www.lethalperformance.com/ind...word=KOO-6003S

 

Yeah those say they're for a Cobra and also say 1 3/4. Most of the Mach headers say 1 5/8. And this setup I found said it was for a 2v with 1 5/8. I guess I wont take the chance lol.

 

You want the same headers as an 03/04 Cobra! Since the Mach 1 has the same heads, it has the same oval shaped exhaust ports. Mine are Kooks 1 3/4" x 3".

 

Ok. So then the 1 3/4 just flow better than the 1 5/8 but both fit?

1 5/8
http://www.americanmuscle.com/bbk-fu...-04-cobra.html

1 3/4
http://www.americanmuscle.com/slp46dolotuh.html

 

just curious what is the problem with the BBK headers there a 1/3 of the cost and a 1 5/8 and how much more power am i going to gain by spending the extra money on a 1 3/4 primary and 3inch collector verses 2.5 collector?

 

Correct, as long as they specify 03/04 cobra / mach 1, you're set.


I would GUESS the difference in power is not very significant. I'd love to see some dyno results to prove me wrong but I doubt it's much on a mild setup. I'm sure it comes more into play for those with built motors and high boost levels.

The main difference that I see is in the quality. A lot of people on here complain that BBK's welds are very ugly looking. My argument is that they are pretty hidden so who cares? In addition to that, the BBK headers are not stainless steel like ARP are - they are ceramic coated. I'm about to buy the BBK headers - I can't justify twice or three times the cost for a better looking part. As long as the performance is close - I'll spend that extra money on a k-member and coilovers.

 

You're asolutely correct. Except any decent long tube header is going to net you about the same power weather you're highly moddified or not.

I know people on here bash BBK's for their welds and what not, but i have several friends (myself included) that run their headers with no problems whatsoever. In fact my one buddy has been running their long tubes for about 5 years with no problems either.

 

Exactly, as long as you get the ones specified for the 03/04 Cobra and Mach 1, you're good. On a mildly modded N/A motor, you probably aren't going to see much of a difference with the larger tubes and collector, but with my blower setup, I needed the better flowing tubes.